Question

我正在尝试在页面上的特定xpath中找到数据。我可以通过请求进入页面。我已经通过使用r.text将源代码打印到我的屏幕并将显示的文本与我正在寻找的文本进行比较来验证我在正确的页面。

r.text返回一个很难提取出我想要的信息的字符串。我被告知lxml是通过xpath搜索信息的方法。不幸的是，我收到了类型错误。

from lxml import html
import requests

payload = {'login_pass': 'password', 'login_user': 'username','submit':'go'}
r = requests.get("website", params=payload)

print r.encoding
tree = html.fromstring(r.text)
print tree
print tree.text_content()

返回

UTF-8
<Element html at 0x10dab8d08>

Traceback (most recent call last):
  File "/Users/Me/Documents/PYTHON/GetImageAsPdf/ImageToPDF_requests_beta.py", line 11, in <module>
    print tree.text_content()
  File "/usr/local/Cellar/python/2.7.6/Frameworks/Python.framework/Versions/2.7/lib/python2.7/idlelib/PyShell.py", line 1343, in write
    return self.shell.write(s, self.tags)
  File "/usr/local/Cellar/python/2.7.6/Frameworks/Python.framework/Versions/2.7/lib/python2.7/idlelib/rpc.py", line 595, in __call__
    value = self.sockio.remotecall(self.oid, self.name, args, kwargs)
  File "/usr/local/Cellar/python/2.7.6/Frameworks/Python.framework/Versions/2.7/lib/python2.7/idlelib/rpc.py", line 210, in remotecall
    seq = self.asynccall(oid, methodname, args, kwargs)
  File "/usr/local/Cellar/python/2.7.6/Frameworks/Python.framework/Versions/2.7/lib/python2.7/idlelib/rpc.py", line 225, in asynccall
    self.putmessage((seq, request))
  File "/usr/local/Cellar/python/2.7.6/Frameworks/Python.framework/Versions/2.7/lib/python2.7/idlelib/rpc.py", line 324, in putmessage
    s = pickle.dumps(message)
  File "/usr/local/Cellar/python/2.7.6/Frameworks/Python.framework/Versions/2.7/lib/python2.7/copy_reg.py", line 70, in _reduce_ex
    raise TypeError, "can't pickle %s objects" % base.__name__
TypeError: can't pickle _ElementUnicodeResult objects

我尝试检查标题

r.headers

返回

{'charset': 'utf-8',
 'x-powered-by': 'PHP/5.3.3',
 'transfer-encoding': 'chunked',
 'set-cookie': 'PHPSESSID=c6i7kph59nl9ocdlkckmjavas1; path=/, LOGIN_USER=deleted; expires=Tue, 15-Oct-2013 15:12:08 GMT; path=/',
 'expires': 'Thu, 19 Nov 1981 08:52:00 GMT',
 'server': 'Apache/2.2.15 (CentOS)',
 'connection': 'close',
 'pragma': 'no-cache',
 'cache-control': 'no-store, no-cache, must-revalidate, post-check=0, pre-check=0',
 'date': 'Wed, 15 Oct 2014 15:12:09 GMT',
 'content-type': 'text/html; charset=UTF-8'}

我的目标是能够通过xpath搜索树，如下所示：

quantity = tree.xpath('/html/body/form[1]/table[3]/tbody[1]/tr/td[2]/table/tbody/tr/td[1]/table/tbody/tr/td/table[1]/tbody/tr[1]/td[2]/strong')

你能帮我辨认我哪里错了吗？

Answer 1

您应该能够将x = x.substring(0, 6) + "/" + x.substring(6, 9) + "/" + x.substring(9, 11);对象转换为常规的可选择的unicode字符串。

使用Python 2，只需用_ElementUnicodeResult包装，例如unicode()

使用Python 3，只需将其包装在print unicode(tree.text_content())中，例如str()

使用lxml处理来自请求的html。 TypeError：无法pickle _ElementUnicodeResult对象

1 个答案: